A permanent-magnet bearing is a mechanical device which enables non-contact relative motion between parts of the device using attractive or repelling forces generated by magnets. Permanent-magnet thrust bearings have been applied to flywheel systems, hard disc drive spindle motors, and magnetically levitated conveyor systems. They are ideally suited to enhance the overall efficiency of the device.
Magnetic bearings are ordinarily constructed using a set of two co-axial permanent-magnet rings as seen, for example, in U.S. Pat. No. 3,614,181 (Meeks). If the two rings are axially aligned, then radially repelling forces between the rings develop, resulting in a radial bearing. If one ring is axially displaced from the other, the direction and magnitude of the radial and axial forces change and, at some axial offset, the set of two rings can be used as a thrust bearing.